Re: Proof using sqrt(2) is irrational

Originally Posted by sakuraxkisu

Prove that\for any rationals x, y, with y not equal to 0, x+y.sqrt(2) is an irrational number.
Suppose x+y.sqrt(2) is rational. Then, since x and y are rational, y.sqrt(2) is also rational, since the difference of two rationals is numbers is also rational.